 /*******************************************************************************
  * Copyright (c) 2005, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - Initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.browser;

 import java.util.ArrayList ;
 import java.util.List ;

 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.ui.browser.BrowserFactory;
 import org.eclipse.ui.browser.IWebBrowser;
 /**
  * @since 1.0
  */
 public class BrowserExt implements IBrowserExt {
     private static final String ATTR_FACTORY_CLASS = "factoryclass"; //$NON-NLS-1$

     private IConfigurationElement element;

     private BrowserFactory delegate;

     /**
      * BrowserExt constructor comment.
      */
     public BrowserExt(IConfigurationElement element) {
         super();
         this.element = element;
     }

     /**
      * Returns the id of this browser.
      *
      * @return java.lang.String
      */
     public String getId() {
         return element.getAttribute("id"); //$NON-NLS-1$
 }

     public String getName() {
         String label = element.getAttribute("name"); //$NON-NLS-1$
 if (label == null)
             return "n/a"; //$NON-NLS-1$
 return label;
     }

     public String getParameters() {
         return element.getAttribute("parameters"); //$NON-NLS-1$
 }

     public String getExecutable() {
         return element.getAttribute("executable"); //$NON-NLS-1$
 }

     public String getOS() {
         String os = element.getAttribute("os"); //$NON-NLS-1$
 if (os == null)
             os = ""; //$NON-NLS-1$
 return os;
     }

     public String [] getDefaultLocations() {
         List list = new ArrayList ();
         IConfigurationElement[] children = element.getChildren("location"); //$NON-NLS-1$
 if (children != null) {
             int size = children.length;
             for (int i = 0; i < size; i++) {
                 list.add(children[i].getValue());
             }
         }

         String [] s = new String [list.size()];
         list.toArray(s);
         return s;
     }

     protected BrowserFactory getDelegate() {
         if (delegate == null) {
             if (element.getAttribute(ATTR_FACTORY_CLASS) == null
                     || element.getAttribute(ATTR_FACTORY_CLASS).length() == 0)
                 return null;

             try {
                 delegate = (BrowserFactory) element
                         .createExecutableExtension(ATTR_FACTORY_CLASS);
             } catch (Exception e) {
                 Trace
                         .trace(
                                 Trace.SEVERE,
                                 "Could not create delegate" + toString() + ": " + e.getMessage()); //$NON-NLS-1$ //$NON-NLS-2$
 }
         }
         return delegate;
     }

     /**
      * Checks whether the factory can work on the user system.
      *
      * @return false if the factory cannot work on this system; for example the
      * required native browser required by browser adapters that it
      * creates is not installed
      */
     public boolean isAvailable() {
         if (delegate == null && (element.getAttribute(ATTR_FACTORY_CLASS) == null
                 || element.getAttribute(ATTR_FACTORY_CLASS).length() == 0))
             return true;
         
         try {
             return getDelegate().isAvailable();
         } catch (Exception e) {
             Trace
                     .trace(
                             Trace.SEVERE,
                             "Error calling delegate " + toString() + ": " + e.getMessage()); //$NON-NLS-1$ //$NON-NLS-2$
 return false;
         }
     }

     /**
      * Obtains a new instance of a web browser.
      *
      * @return instance of IBrowser
      */
     public IWebBrowser createBrowser(String id, String location,
             String parameters) {
         try {
             return getDelegate().createBrowser(id, location, parameters);
         } catch (Exception e) {
             Trace
                     .trace(
                             Trace.SEVERE,
                             "Error calling delegate " + toString() + ": " + e.getMessage()); //$NON-NLS-1$ //$NON-NLS-2$
 return null;
         }
     }

     /**
      * Return a string representation of this object.
      *
      * @return java.lang.String
      */
     public String toString() {
         String s = "BrowserExt: " + getId() + ", " + getName() + ", " + getOS() //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
 + ", " + getExecutable() + ", " + getParameters() + ", "; //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
 String [] locations = getDefaultLocations();
         if (locations != null) {
             int size = locations.length;
             for (int i = 0; i < size; i++) {
                 s += locations[i] + ";"; //$NON-NLS-1$
 }
         }
         return s;
     }
 }

